U.S. patent application number 13/877890 was filed with the patent office on 2014-02-20 for apparatus for preventing over inflation of the retention balloon in medical catheters and airway devices.
This patent application is currently assigned to ConvaTec Technologies, Inc.. The applicant listed for this patent is ConvaTec Technologies, Inc. Invention is credited to John B. Cline, Christopher Gregory, Yun Jin.
Application Number | 20140052063 13/877890 |
Document ID | / |
Family ID | 48430138 |
Filed Date | 2014-02-20 |
United States Patent
Application |
20140052063 |
Kind Code |
A1 |
Gregory; Christopher ; et
al. |
February 20, 2014 |
APPARATUS FOR PREVENTING OVER INFLATION OF THE RETENTION BALLOON IN
MEDICAL CATHETERS AND AIRWAY DEVICES
Abstract
The body has a fluid inlet port for receiving pressurized fluid
and a fluid outlet port connected to the retention balloon. A first
passage connects the fluid inlet port and the fluid outlet port. A
second passage in the body is connected to the balloon fluid return
path and is at the pressure of the retention balloon. A valve
prevents fluid flow through the first passage when actuated. The
valve includes a pressure-responsive member movable to a position
to obstruct fluid flow in response to fluid pressure in the second
passage exceeding the predetermined level. Flexible means such as a
membrane defines a normally open portion of the first fluid
passage, which is closed by the moveable means bearing on the
membrane when pressure exceeding the predetermined level actuates
the valve.
Inventors: |
Gregory; Christopher;
(Newtown, PA) ; Jin; Yun; (Bedminister, NJ)
; Cline; John B.; (New Brunswick, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ConvaTec Technologies, Inc |
Las Vegas |
CA |
US |
|
|
Assignee: |
ConvaTec Technologies, Inc.
Las Vegas
NV
|
Family ID: |
48430138 |
Appl. No.: |
13/877890 |
Filed: |
November 15, 2012 |
PCT Filed: |
November 15, 2012 |
PCT NO: |
PCT/US12/65239 |
371 Date: |
May 30, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61560489 |
Nov 16, 2011 |
|
|
|
Current U.S.
Class: |
604/99.03 ;
604/99.01; 604/99.02 |
Current CPC
Class: |
A61M 16/209 20140204;
A61M 16/044 20130101; A61F 2005/4455 20130101; A61M 25/10187
20131105; A61F 5/449 20130101; A61M 25/10182 20131105; A61M 16/0486
20140204; A61F 5/445 20130101; A61M 3/0295 20130101; A61M 25/10185
20131105; A61M 16/208 20130101; A61M 16/0443 20140204; A61M 16/04
20130101; A61M 25/10183 20131105; A61M 2205/583 20130101; A61M
16/201 20140204 |
Class at
Publication: |
604/99.03 ;
604/99.01; 604/99.02 |
International
Class: |
A61M 29/00 20060101
A61M029/00; A61M 16/04 20060101 A61M016/04 |
Claims
1. (canceled)
2. (canceled)
3. Apparatus for limiting fluid pressure in the medical catheter
retention balloon designed for use with a source of pressurized
fluid having a connector associated therewith, wherein the catheter
has a supply fluid path from the apparatus for filling the balloon
and a return fluid path communicating with the balloon connected to
the apparatus, the apparatus comprising: a body with a fluid inlet
port for receiving the connector associated with the pressurized
fluid source and a fluid outlet port; a first passage connecting
said fluid inlet port and the fluid outlet port of said body; a
second passage connected to said return fluid path; and means for
preventing fluid flow through said first passage when the fluid
pressure in said second passage exceeds a predetermined level,
wherein said fluid flow preventing means comprises means for
moveable said second passage into a first portion connected to said
return fluid path and a second portion, said moveable means being
movable between a first position, wherein fluid flow through said
first passage is not obstructed, and a second position wherein
fluid flow through said first passage is obstructed, said moveable
means being moved from said first position to said second position
in response to fluid pressure in said first portion of said second
passage exceeding said given level, and wherein the apparatus
further comprises flexible means located in said second portion of
said second passage, said flexible means defining a normally open
portion of said first fluid passage, which portion is closed by
said moveable means bearing on said flexible means when said
moveable means is in said second position.
4. The apparatus for claim 3 wherein said first passage comprises a
first section connected to said supply fluid path, and a second
section connected to said return fluid path, and wherein said
normally open portion of said first fluid passage at least
partially defines a connection between said first section of said
first passage and said second section of said first passage.
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. The apparatus of claim 3 wherein said flexible means comprises a
membrane.
10. The apparatus of claim 3 further comprising means situated in
said second portion of said second passage for concentrating the
effect of said moveable means on said flexible means.
11. The apparatus of claim 10 wherein said concentrating means
comprises a plastic disc.
12. (canceled)
13. The apparatus of claim 4 further comprising a one-way valve
situated in said first section of said first passage for preventing
fluid flow between said first section and said second section of
said first passage, except through said connection defined by said
flexible means, when said pressurized fluid source is connected to
said fluid inlet port of said body to inflate said balloon.
14. (canceled)
15. The apparatus of claim 4 wherein said first section of said
first passage comprises first and second branches, wherein said
second section of said first passage comprises first and second
branches, wherein said connection comprises a connection between
said first branch of said first section and said first branch of
said second section, and further comprising a structure comprising
a surface situated over said branches upon which said flexible
means is supported, said surface having ports aligned with said
first and second branches of said first section and said first and
second branches of said second section, respectively, and a
retainer for holding said flexible means on said structure surface,
said retainer having a first opening aligned with said ports
aligned with said first branch of said first section and said first
branch of said second section, such that said moveable means causes
said membrane to close the connection between said port aligned
with said first branch of said first section and said port aligned
with first branch of said second section, when said moveable means
is in said second position.
16. The apparatus of claim 15 wherein said membrane has a hole
aligned with said port aligned with said second branch of said
second section, and wherein said retainer comprises a second
opening situated over said hole in said membrane.
17. The apparatus for claim 15 further comprising means for
allowing fluid to be withdrawn from said balloon when said moveable
means is in said first position.
18. An apparatus for limiting fluid pressure in the medical
catheter retention balloon designed for use with a source of
pressurized fluid having a connector associated therewith, wherein
the catheter has a supply fluid path from the apparatus for filling
the balloon and a return fluid path communicating with the balloon
connected to the apparatus, the apparatus comprising: a body with a
fluid inlet port for receiving the connector associated with the
pressurized fluid source and a fluid outlet port; a first passage
connecting said fluid inlet port and the fluid outlet ort of said
body; a second passage connected to said return fluid path; and
means for preventing fluid flow through said first passage when the
fluid pressure in said second passage exceeds a predetermined
level, wherein the apparatus further comprises a pressure relief
valve located in said second passage, and wherein said fluid flow
preventing means comprises a first valve and a second valve, said
first valve being situated in said first passage between said fluid
input port and said fluid outlet port, said second valve being
situated in said second passage between said balloon fluid outlet
and said pressure relief valve, and means for connecting said first
valve and said second valve to move together from a closed position
to an open position in response to the connector associated with
the pressurized fluid source being received in said fluid inlet
port of said body.
19. The apparatus of claim 18 further comprising means for urging
said first valve and said second valve to move from said open
position to said closed position.
20. The apparatus of claim 18 further comprising mechanical means
connecting said first valve and said second valve, said mechanical
means extending between said first passage and said second passage,
and further comprising means for sealing said first passage from
said second passage.
21. The apparatus of claim 18 wherein said second valve comprises a
duckbill valve.
22-53. (canceled)
54. An apparatus for limiting fluid pressure in the medical
catheter retention balloon designed for use with a source of
pressurized fluid having a connector associated therewith, wherein
the catheter has a supply fluid path from the apparatus for filling
the balloon and a return fluid path communicating with the balloon
connected to the apparatus, the apparatus comprising: a body with a
fluid inlet port for receiving the connector associated with the
pressurized fluid source and a fluid outlet port; a first passage
connecting said fluid inlet port and the fluid outlet port of said
body; a second passage connected to said return fluid path; and
means for preventing fluid flow through said first passage when the
fluid pressure in said second passage exceeds a predetermined
level, wherein said fluid flow preventing means comprises a
normally open valve situated in said first passage between said
fluid input port and said fluid outlet port, means situated in said
second passage moveable between a normal position and a second
position, and means for connecting said moveable means and said
valve for closing said valve when said moveable means is moved to
said second position by the fluid pressure in said second passage
exceeding said given level, and wherein said moveable means
comprises bistable means.
55. The apparatus of claim 54 wherein said bistable means comprises
a dome-shaped member.
56. The apparatus of claim 55 wherein said dome-shaped member is
formed of rigid or semi-rigid material.
57. The apparatus of claim 55 wherein said moveable means further
comprises a diaphragm situated proximate said dome-shaped
member.
58. An apparatus for limiting fluid pressure in the medical
catheter retention balloon designed for use with a source of
pressurized fluid having a connector associated therewith, wherein
the catheter has a supply fluid path from the apparatus for filling
the balloon and a return fluid path communicating with the balloon
connected to the apparatus, the apparatus comprising: a body with a
fluid inlet port for receiving the connector associated with the
pressurized fluid source and a fluid outlet port; a first passage
connecting said fluid inlet port and the fluid outlet port of said
body; a second passage connected to said return fluid path; and
means for preventing fluid flow through said first passage when the
fluid pressure in said second passage exceeds a predetermined
level, wherein said fluid flow preventing means comprises a valve
in said first passage between said fluid inlet port and said fluid
outlet port, an inflatable balloon situated in said second passage
and connected to said fluid outlet of said balloon and means for
connecting said balloon in said second passage and said valve such
that said valve is closed by the inflation of said balloon in said
second passage, when the fluid pressure in said balloon fluid
outlet exceeds said given pressure level.
59. The apparatus of claim 58 wherein said balloon in said second
passage defines a central opening through which said connecting
means extends.
60. An apparatus for limiting fluid pressure in the medical
catheter retention balloon designed for use with a source of
pressurized fluid having a connector associated therewith, wherein
the catheter has a supply fluid path from the apparatus for filling
the balloon and a return fluid path communicating with the balloon
connected to the apparatus, the apparatus comprising: a body with a
fluid inlet port for receiving the connector associated with the
pressurized fluid source and a fluid outlet port; a first passage
connecting said fluid inlet port and the fluid outlet port of said
body; a second passage connected to said return fluid path; and
means for preventing fluid flow through said first passage when the
fluid pressure in said second passage exceeds a predetermined
level, wherein said first passage comprises a flexible tube and
wherein said fluid flow preventing means comprises a balloon in
said second passage connected to said balloon fluid outlet, said
balloon in said second passage closing said flexible tube when
inflated by pressurized fluid in said balloon fluid outlet
exceeding said given level.
61. The apparatus of claim 60 wherein said flexible tube comprises
first and second substantially parallel sections connected by a "U"
shaped section,
62. The apparatus of claim 60 further comprising a pressure plate
interposed between said balloon in said second passage and said
flexible tube.
63. The apparatus of claim 62 further comprising a pressure
indicator associated with said pressure plate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed on Provisional Patent Application Ser.
No. 61/560,489, filed Nov. 16, 2011.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to medical devices with
inflatable retention balloons and more particularly to an apparatus
for preventing over inflation of the catheter retention balloons in
a fecal management system or an endotracheal rube.
[0004] 2. Description of Prior Art Including Information
[0005] Fecal management systems, such as the one disclosed in U.S.
Pat. No. 8,016,816, issued Sep. 13, 2011 to Christopher C. Gregory,
which patent is incorporated herein by reference, are known in the
art. The system disclosed in the Gregory patent is a medical
appliance formed of an elongated flexible tubular element or
catheter having a distal end designed to be introduced into a body
cavity, such as the rectum through the anal sphincter. The proximal
end of catheter is connected to a receptacle for the collection of
fecal waste.
[0006] Affixed to the exterior surface of the distal end of the
catheter is an inflatable balloon which serves to retain the distal
end of the catheter within the body cavity. The balloon is inflated
to a suitable diameter with fluid, such as air, water or saline,
through a fluid supply tube or lumen, after it is inserted into the
body cavity. The supply lumen is connected to a source of
pressurized inflation fluid, such as a syringe. The syringe is also
used to withdraw the inflation fluid through the supply lumen, to
deflate the balloon.
[0007] A second lumen may be provided to deliver irrigation fluid
to the body cavity. One end of irrigation lumen extends through a
port in the distal end of the catheter. The other end is connected
to a source of irrigation fluid.
[0008] The distal end of the catheter and the retention balloon are
both made entirely of soft, compliant material, for example,
silicone, so as not to injure any body tissue.
[0009] The retention balloon surrounds the distal end of the
catheter and preferably has a toroidal shape when fully inflated.
The wall of the balloon may be fabricated in its fully inflated
shape of material that allows the balloon to be inflated to its
final shape.
[0010] Fecal management systems using an inflated retention balloon
must be used carefully because they can create too much pressure on
the rectal tissue if the retention balloon is over inflated. That
pressure is a result of the balloon being filled with a volume of
fluid greater the space available in the body cavity. Accordingly,
all fecal management systems have an indicated maximum volume for
the retention balloon that each manufacturer has established as
safe, However, this maximum balloon volume can be exceeded by over
inflating the balloon, resulting in damage to the soft tissue
surrounding the balloon.
[0011] Similarly, endotracheal tubes have affixed to the exterior
surface of the distal end of the catheter an inflatable balloon
which serves to retain the distal end of the catheter within the
body cavity and create an air seal to the trachea. The balloon is
inflated to a suitable diameter with fluid, such as air, through a
fluid supply tube or lumen, after it is inserted into the trachea.
The supply lumen is connected to a source of pressurized inflation
fluid, such as a syringe. The syringe is also used to withdraw the
inflation fluid through the supply lumen, to deflate the balloon.
In an endotracheal tube, the retention balloon surrounds the distal
end of the catheter and preferably has a toroidal shape when fully
inflated. The wall of the balloon may be fabricated in its fully
inflated shape of material that allows the balloon to be inflated
to its final shape.
[0012] Endotracheal systems using an inflated retention balloon
must be used carefully because they can create too much pressure on
the mucosal tissue in the trachea if the retention balloon is over
inflated. That pressure is a result of the balloon being filled
with a volume of fluid greater the space available in the trachea.
Accordingly, all endotracheal tubes have an indicated maximum
volume for the retention balloon that each manufacturer has
established as safe or pressure monitoring mechanisms. However,
this maximum balloon volume or pressure can be exceeded by over
inflating the balloon, resulting in damage to the soft tissue
surrounding the balloon.
[0013] Although one commercially available fecal management system
(Flexi-Seal.RTM. SIGNAL.TM. FMS) can be obtained with an indicator
that tells the clinician when the balloon is properly filled, there
continue to be cases where clinicians have initially over inflated
the retention balloon, or have added more fluid to the balloon
after the catheter has been in use, resulting in a potentially
hazardous situation.
[0014] Another disclosed system employs a catheter with a pressure
relief valve. However, that approach has not proved to be practical
because in use there are frequently brief periods of muscle
contraction in the rectum that result in high pressure in the
balloon. In the trachea there are periods of high pressure during
the respiratory cycle. If the inflation fluid were allowed to
escape under those high pressure conditions, the retention of the
device would be compromised and the catheter expelled or the seal
lost. Accordingly, neither of these approaches has proved
successful.
[0015] Another possible approach to the over inflation problem
would be to electronically measure the amount of inflation fluid
provided to the balloon. Accurate measurement of the volume of a
flowing fluid through a tube requires the measurement of the flow
rate of the fluid and of the time during which the fluid is
flowing. Those values can then be multiplied to calculate the total
volume of fluid that has passed through the tube. This is typically
done through real time electronic measurement of the flow rate
which utilizes the cooling ability of the fluid across a heated
probe, and a microprocessor completing the calculations.
[0016] For prevention of the delivery of too much fluid, the result
of this calculation then has to control a valve or actuate an alarm
to prevent additional fluid, from being added to the balloon.
Clearly, devices using this method of calculating the amount of
fluid used to inflate the balloon are complex and costly. Moreover,
they have difficulty in taking into account the fact that the fluid
can and needs to be able to be withdrawn from the balloon, as well
as provided to the balloon, because they cannot easily
differentiate between the flow directions. Simpler and less
expensive options are desirable, and are provided by the present
invention.
[0017] The present invention relates to apparatus designed for use
as pan of a fecal management system or endotracheal tube of the
type including a catheter with an inflatable retention balloon. The
apparatus is utilized as pan of the fluid inflation system and
several different device configurations and modes of operation are
disclosed which prevent over inflation of the retention balloon by
limiting the flow of inflation fluid to the catheter balloon to a
specific volume or pressure.
BRIEF SUMMARY OF TIM INVENTION
[0018] Two different basic approaches are proposed to prevent over
inflation of the catheter retention balloon. One approach involves
monitoring the fluid pressure in the balloon as it is filled from a
source of pressurized fluid and preventing additional fluid from
entering, the balloon after a predetermined pressure level in the
balloon is reached. The other approach involves monitoring the
volume of fluid provided to the balloon and preventing additional
fluid from entering the balloon after a predetermined volume of
fluid has been provided to the balloon.
[0019] In a first preferred embodiment of the present invention
using, the pressure monitoring approach, the apparatus is
incorporated in the fill port of the catheter to prevent over
inflation of the catheter retention balloon by monitoring the
pressure in the balloon. It utilizes the pressure in a fluid
connection to the balloon, which connection includes a return lumen
separate from the supply lumen, to close a valve in the fill line
to stop the flow of fluid into the balloon when the pressure in the
balloon exceeds a pre-determined level.
[0020] Fluid under pressure is supplied to the inlet port of the
apparatus body. A valve in the pressure cap of the body is secured
to the base of the body to create a path to carry fluid from the
inlet port of the body to the outlet port of the body, the latter
of which is connected to the supply lumen of the balloon. The valve
utilizes a pressure responsive deformable member which moves to a
position to press on a flexible membrane to seal the fluid flow
path to prevent over filling of the retention balloon.
[0021] The deformable member has an area significantly larger than
the flow area under the membrane to permit the lower pressure in
the balloon to stop the higher pressure fluid flow. Preferably, the
moveable member which presses on the membrane is a dome or other
structure which deforms suddenly when a predetermined pressure
level is reached. Most preferably, the structure incorporates or is
made as a snap dome which is bi-stable such that it can move
between two positions, one of which is remote from the membrane,
and thus does not block the fill line, and the other of which bears
on the membrane to block the fluid flow.
[0022] The apparatus body is built out of two molded parts that do
not have fluid flow passing between them, except through the
catheter balloon. An integrated indicator that signals prior to or
simultaneous with the valve closing off may be provided.
[0023] A check valve is used to control the flow path to permit
removal of fluid from the balloon through the supply lumen to
deflate the balloon. The check valve element may be a ball, flap,
duck bill, or umbrella valve, as described in detail below. The
check valve element may also consist of two or more separate flow
channels employed in conjunction with the flexible membrane, as
disclosed in one version of the preferred embodiments.
[0024] Preferably, the deformable structures of the apparatus are
molded silicone rubber, polyurethane or other thermoplastic
elastomer.
[0025] More specifically, apparatus for preventing over inflation
of the catheter retention balloon of a fecal management system is
provided. The fecal management system is of the type designed for
use with a source of pressurized fluid having an associated
connector. The retention balloon has a fluid port to the supply
line and a fluid port to the return line. The apparatus body has a
fluid inlet port for receiving the connector associated with the
pressurized fluid source and a fluid outlet port connected to the
fluid supply line of the balloon. The body has a first flow passage
which connects the fluid inlet port and the fluid outlet port to
permit fluid to be provided to the retention balloon during
inflation and removed from the retention balloon during deflation.
A second chamber in the body is connected to the fluid return of
the balloon by a return lumen such that it is at or very close to
the same fluid pressure as the retention balloon. The chamber
maintains a pressure very close to the balloon pressure since,
there is very little flow in the return line resulting in minimal
pressure drop through the return line. Means are provided for
preventing fluid flow through the first passage of the body when
the fluid pressure in the second chamber of the body exceeds a
pre-determined pressure level.
[0026] The fluid flow preventing means may take a variety of forms.
In one preferred embodiment, moveable means are provided for
dividing the second or return chamber into a first portion
connected to the fluid return port of the balloon and a second
portion. The moveable means is movable between a first position,
wherein fluid flow through the first passage is not obstructed, and
a second position, wherein fluid flow through the first passage is
prevented. The moveable means is moved from its first position to
its second position in response to fluid pressure in the first
portion of the second chamber exceeding the predetermined pressure
level.
[0027] Flexible means are located in the second portion of the
second chamber. The flexible means defines a normally open portion
of the first fluid passage. That portion of the first fluid passage
is closed by the moveable means bearing on the flexible means, when
the moveable means is in its second position.
[0028] The first passage includes a first section connected to the
fluid inlet port of the body and a second section connected to the
fluid outlet port of the body. The normally open portion of the
first fluid passage at least partially defines a connection between
the first section of the first passage and the second section of
the first passage.
[0029] The moveable means is situated either in the first position
or in the second position. Means are associated with the moveable
means for urging the moveable means toward its first position.
[0030] In one version of this preferred embodiment, the moveable
means takes the form of a dome-shaped member. The dome-shaped
member is formed of rigid or semi-rigid material.
[0031] The flexible means may take the form of a membrane. Means
situated in the second portion of the second passage are provided
for concentrating the effect of the moveable means on the flexible
means.
[0032] Means for venting the second portion of the second chamber
are provided to allow air that would otherwise be trapped in the
second portion of the second chamber under the moveable means to
escape, such that the moveable means can move from its first
position to its second position.
[0033] A one-way check valve is situated between the sections of
the first passage. That valve prevents fluid flow from the first
section of the first passage to the second section of the first
passage, except through the connection defined by the flexible
means, when the pressurized fluid source is connected to the fluid
inlet port to inflate the retention balloon.
[0034] Pressure indicating means may be associated with the first
portion of said second chamber.
[0035] In another version of the first preferred embodiment, the
sections of the first passage are each divided into first and
second branches. The connection between the sections of the first
passage is a connection between the first branch of the first
section and the first branch of the second section. A structure,
including a surface situated over the branches, is provided to
support the flexible means. The surface has ports aligned with the
first and second branches of the first section and with the first
and second branches of the second section, respectively. A retainer
is provided for holding the flexible means in place on the
structure surface. The retainer has a first opening situated over
the ports aligned with the first branch of the first section and
the first branch of the second section. The moveable means causes
the membrane to close the connection between the port. aligned with
the first branch of the first section and the port aligned with the
first branch of the second section, when the moveable means is in
the second position.
[0036] The flexible means has a hole situated over the port aligned
with the second branch of the second section. The retainer also
includes a second opening situated over the hole in the flexible
means.
[0037] The multiple branch structure eliminates the necessity of a
discrete fill check valve between the sections of the first
passage. It allows the moveable means and flexible means to prevent
fluid flow through the first passage when the given pressure level
is exceeded and at the same time allows fluid to be withdrawn from
the balloon to deflate the balloon when the moveable means is in
its first position.
[0038] In the second preferred embodiment of the present invention,
the fill volume is set during balloon inflation and fluid resulting
in excess pressure is allowed to escape, but only during the
inflation process. This prevents over inflation of the retention
balloon by limiting the amount of fluid retained in the balloon
according to the pressure in the balloon. During the inflation
process, fluid in the balloon has access to a pressure relief valve
but the balloon fluid is isolated from the relief valve once the
inflation process is ended. Thus, surges in pressure during normal
use do not deflate the balloon and the device remains viable.
[0039] The preferred configuration is to not make the connection
between the pressure relief valve and the balloon through the
supply lumen as the pressure drop through the supply lumen is very
large during inflation. This large pressure drop would easily
result in the fluid flowing out of the pressure relief valve,
rather than to the retention balloon.
[0040] In one version, the insertion into the fluid inlet port of
the body of the connector associated with the source of pressurized
fluid, typically a syringe, opens two valves. The first valve is
situated in the fluid passage between the syringe and the retention
balloon. That valve prevents the fluid from spilling out of the
balloon once the syringe is removed. The second valve is situated
in a return passage from the balloon, in series with the return
line and the pressure relief valve.
[0041] The second valve is held open only when the syringe is
received in the port. Holding the second valve open enables the
pressure relief valve to prevent overpressure in the balloon. The
dual syringe actuated valves are connected mechanically but the
fluid path from one to the other flows through the balloon when
open. When the second valve is closed, the flow of fluid to the
pressure relief valve is stopped. The pressure then equalizes
throughout the system and flow between the two valves becomes
irrelevant.
[0042] The mechanical opening of the second valve can be done by an
external element of the syringe pressing against a mechanical
element. This introduces some probability of user interference with
the mechanism, so shielding of these elements can be used to
prevent user interference with the mechanism.
[0043] In a specific configuration, the mechanism that moves when
the syringe forces the first valve open extends on to act as the
driving element for the second valve. In a syringe actuated valve,
during connection the syringe tip presses on the stem of the valve
pushing the stem's sealing surface away from the valve seat thus
opening the valve and allowing fluid to pass through. The valve
stem has a return and sealing force from a spring located or
integrated behind the stem.
[0044] There is an extension to the stem that extends through the
core of the spring, and passes through an opening a wall in the
body with a seal into another chamber. In the second chamber, the
extended stem tip interfaces with a second seal. When the syringe
tip pushes the stem in, the motion continues through to the second
chamber and the extended tip lifts a second seal off of its seat.
Opening this second valve opens the path to the pressure relief
valve.
[0045] The seal between the two chambers is only relevant when the
syringe is connected. To ensure that seal, the stem has a
conforming feature that seals the opening between the chambers as
the stem moves to its open position. Disconnecting the syringe
allows the stem to return to its normal position, sealing both
valves, and isolating the pressure relieve valve from the return
flow path.
[0046] In another version, the mechanism that moves when the
syringe forces the first valve open extends on to act as the
driving element for the second valve which is in the form of a
"duckbill" valve. In a syringe actuated valve, during connection
the syringe tip presses on the stem of the valve pushing the stem's
sealing surface away from the valve seat thus opening the valve and
allowing fluid to pass through. The valve stem has a return and
sealing force from a spring located or integrated behind the
stem.
[0047] In this version, there is an extension to the stem that
extends through the core of the spring, passes through a wall with
a seal into another chamber. In the second chamber, the extended
stem tip interfaces with the side of a duckbill valve. When the
syringe tip pushes the stem in, the motion continues through to the
second chamber and the extended tip deforms the duckbill valve,
opening it. Opening this second valve opens the fluid flow path to
the pressure relief valve. The seal between the two chambers is
only relevant when the syringe is connected. Disconnecting the
syringe allows the stem to return to its normal position, sealing
both valves and isolating the pressure relieve valve from the
return flow path.
[0048] In another version, if the pressure in the return line
exceeds a predetermined limit, it can force a path through a
pressure relief umbrella valve but only if it can then pass on
through a flow valve in the fluid escape path. The flow valve,
which takes the form of a "duckbill" valve, is opened only when the
fluid supply system (syringe) is attached. Connecting the syringe
depresses a lever that drives a pin through the duckbill, forcing
it open to allow fluid flow out of the system. The duckbill valve
could also be replaced by a spring actuated flow valve that
prevents flow out of the system unless the pin pushes the valve
open. The flow valve and the pressure relief valve can be
interchanged in order on the return line without detrimental effect
to the functioning of the system.
[0049] In another version, the pressure in the return line is used
to close a valve on the fill port preventing the overfilling of the
balloon. The flow in the return line to the second chamber
pressurizes the area under the dome. Once the pressure is
sufficient to overcome the moving membrane return forces and the
dome return force, the stem is pulled forcing it against the second
valve seat stopping flow. The high pressure in the first chamber
would force the stem into the closed position if it were not for
the counterbalancing effect of the two moving membrane seals. The
only forces acting on the stem is the pull from the membrane dome
and the spring tierce of the membrane seals.
[0050] In another embodiment, the pressure in the return line is
used to inflate a return balloon that actuates a valve system to
stop flow into the retention balloon. The return balloon expands
under pressure and pulls the stem closing the valve and stopping
flow to the retention balloon. Further fluid supplied through the
Luer valve only forces the second valve more tightly closed.
Pulling fluid out of the supply passage will create enough vacuum
to overcome the sealing of the second valve, opening it and
allowing the fluid to be extracted from the catheter.
[0051] The return balloon preferably has a toroidal or annular
shape with the stem passing through the center opening. Other
configurations of the return balloon are just as viable such as a
nearly closed "C" shape to allow easy assembly.
[0052] In another version of this embodiment, the pressure in the
return line is used to inflate a return balloon that crimps a piece
of tubing in the fluid supply path. The return fluid pressure
expands the return balloon. The expanding return balloon presses a
pressure plate against the bend of the supply tubing crimping it
and stopping flow. The large area of the return balloon and the
small area of the supply tubing allow the low return pressure to
block the high pressure supply tubing. A separate one-way valve
connecting the fluid input side of the supply tubing with the
return line allows fluid to be withdrawn from the system reducing
the pressure in the return balloon and thus reopening the supply
tubing.
[0053] In a further embodiment, the pressure in the return line is
used to deflect a flexible element. The flexible element forces a
valve to close against a port in the retention balloon inflation
line. The flexible element can be connected to the valve via a push
rod. The push rod may or may not be fixed to either the flexible
element or the valve. The valve may be a poppet valve with a stem,
where the stem includes sealing means that prevents leakage of
fluid out of the system.
[0054] Alternatively, the valve may be sealed by means of a
flexible diaphragm, a balloon, or any flexible element that deform
with sufficient force when pressurized to apply sealing force to
the valve. The flexible element can bear against an over-center
spring that is displaced when a predetermined force is applied to
it. The spring allows the valve to remain open until it is forced
closed under sufficient balloon pressure.
[0055] The spring may be a disc, a dome, a leaf spring, or any
spring configuration that can be significantly displaced when a
predetermined force is applied. The spring may be configured to
return to its rest position once applied force drops below the
threshold level. Or it may be a bi-stable spring that requires
manual resetting. This configuration allows the valve to stay fully
open regardless of fill pressure or fill flow rate, and causes it
to close rapidly when the retention balloon reaches the desired
pressure, regardless of fill pressure or flow rate.
[0056] Turning now to volume monitoring approaches, rather than
involve electronics, in one preferred embodiment a paddle wheel
flow indicator is used to drive a mechanism that controls a valve.
All the flow in and out of the balloon is forced to pass through a
paddle wheel or similar component. The fluid flowing through forces
the wheel to turn. If the fluid is incompressible and cannot leak
around the wheel, the amount of rotation will be an exact
indication of the amount of fluid that has passed through the
device. The motion of the wheel is then used to drive a valve stem
that shuts off the flow once a predetermined total volume is
achieved. There is an accumulator of flexible construction between
the wheel and the valve so that enough fluid can be withdrawn (from
the accumulator) with the valve closed so that the wheel can open
the valve for fluid withdrawal.
[0057] In another preferred embodiment, the retention balloon is
supplied in a closed form with the maximum allowable amount of
inflation fluid already in the system. The inflation system has a
reservoir that is permanently connected to the supply line. Once
the retention balloon is inserted, the fluid is transferred from
the external reservoir to the internal retention balloon and an
interconnecting valve is closed. For removal, the fluid is
transferred back from the retention balloon to the external
reservoir. As the device needs to be re-inflatable, this process
can be repeated.
[0058] A number of structures can be used to act as the reservoir.
The reservoir may be a collapsible structure which the clinician
squeezes or applies pressure to in order to force the fluid into
the retention balloon. The collapsible reservoir is either spring
loaded or of a spring back structure so that it can draw the fluid
out for removal. This configuration can also be combined with a
pressure responsive indicator allowing customization of the fill
volume with less than the total fluid in the reservoir.
[0059] In an alternate version, the reservoir is similar to a
syringe with a bellows-like portion. The clinician applies force on
the bellows-like portion to push the fluid into the retention
balloon or remove fluid from the retention balloon. The syringe is
permanently attached so a valve or clamp is used to hold the fluid
in the reservoir or balloon.
[0060] The present invention may also be used with other medical
catheters to limit the fill volume to a specific volume or pressure
wherein the medical catheter has a fluid filled balloon requiring
prevention from overfill.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF DRAWINGS
[0061] To these and to such other objects that may hereinafter
appear, the present invention relates to apparatus for preventing
over inflation of the catheter retention balloon in a fecal
management system or in an endotracheal tube as described in detail
in the following specification, and recited in the annexed claims,
taken together with the accompanying drawings, in which like
numerals refer to like parts and in which:
[0062] FIG. 1 is an elevation view of a typical fecal management
system with the over Inflation preventing apparatus of the present
invention;
[0063] FIG. 2 is a cross-sectional view of the catheter of the
fecal management system of FIG. 1;
[0064] FIG. 3 is a cross-sectional view of a first version of the
first preferred embodiment of the present invention;
[0065] FIG. 4 is a cross-sectional view of a second version of the
first preferred embodiment of the present invention;
[0066] FIG. 5 is a cross-sectional view of a third version of the
first preferred embodiment of the present invention;
[0067] FIG. 6 is an exploded view of a fourth version of the first
preferred embodiment of the present invention;
[0068] FIG. 7 is a cross-sectional view of the fourth version of
the first preferred embodiment of the present invention shown in
FIG. 6;
[0069] FIGS. 8a-8c are images showing the details of the branches
and flow paths of the fourth version of the first preferred
embodiment of the present invention, shown in FIG. 7;
[0070] FIG. 9 is a cross-sectional view of a first version of the
second preferred embodiment of the present invention;
[0071] FIG. 10 is a cross-sectional view of a second version of the
second preferred embodiment of the present invention;
[0072] FIG. 11 is a cross-sectional view of a first version of the
third preferred embodiment of the present invention;
[0073] FIG. 12 is a cross-sectional view of a second version of the
third preferred embodiment of the present invention:
[0074] FIG. 13 is a cross-sectional view of a third version of the
third preferred embodiment of the present invention;
[0075] FIG. 14 is a cross-sectional view of a fourth version of the
third preferred embodiment of the present invention;
[0076] FIG. 15 is a cross-sectional view of a first version of the
fourth preferred embodiment of the present invention;
[0077] FIG. 16 is a cross-sectional view of a second version of the
fourth preferred embodiment of the present invention;
[0078] FIG. 17 is a perspective view of the second version of the
fourth preferred embodiment of the present invention;
[0079] FIG. 18 is a cross-sectional view of a first version the
fifth preferred embodiment of the present invention, showing same
during and after inflation of the balloon;
[0080] FIG. 19 is a cross-sectional view of a second version of the
fifth preferred embodiment of the present invention;
[0081] FIG. 20 is an elevation view of the sixth preferred
embodiment of the present invention, showing the apparatus during
inflation;
[0082] FIG. 21 is an elevation view of the sixth preferred
embodiment of the present invention, showing the apparatus after
inflation;
[0083] FIG. 22 is a perspective view of the sixth preferred
embodiment of the present invention;
[0084] FIG. 23 is an exploded view of the sixth preferred
embodiment of the present invention:
[0085] FIG. 24 is a detailed view showing the cam follower member
of the sixth preferred embodiment of the present invention in the
closed position;
[0086] FIG. 25 is a detailed view showing the cam follower member
of the sixth preferred embodiment of the present invention in the
open position;
[0087] FIG. 26 is a perspective view of the seventh preferred
embodiment of the present invention, showing the collapsible
reservoir prior to inflation;
[0088] FIG. 27 is a perspective view of the seventh preferred
embodiment of the present invention, showing the collapsible
reservoir after the balloon is inflated;
[0089] FIG. 28 is a perspective view of the seventh preferred
embodiment of the present invention, showing the collapsible
reservoir during deflation of the balloon;
[0090] FIG. 29 is a perspective view of the eighth preferred
embodiment of the present invention, showing a sealed syringe fluid
source prior to inflation; and
[0091] FIG. 30 is a perspective view of the eighth preferred
embodiment of the present invention, showing the sealed syringe
fluid source during balloon inflation.
DETAILED DESCRIPTION OF THE INVENTION
[0092] The present invention is designed for use as part of a
tubular medical device which utilizes an inflatable retention
balloon. The basic components of one such system are illustrated in
FIG. 1. The system is a medical appliance formed of an elongated
flexible tubular element or catheter, generally designated A,
having a distal end 10 which is introduced into a body cavity, such
as the rectum through the anal sphincter or the trachea through the
mouth. The proximal end 12 of catheter A is connected to a
receptacle, generally designated B, for the collection of fecal
waste or an respiratory management system for an endotracheal tube.
Affixed to the exterior surface of the distal end 10 of catheter A
is a low-pressure inflatable retention balloon 14, shown in its
inflated state.
[0093] Balloon 14 is inflated to a suitable diameter with fluid,
such as air, water or saline, through a fluid supply lumen 16 after
the balloon is inserted into the body cavity such that the distal
end of the catheter is retained in place within the body cavity.
One end of supply lumen 16 is connected to a source of pressurized
inflation fluid, shown in the figure as a syringe 18. The syringe
is also used to withdraw the inflation fluid, to deflate the
balloon, through supply lumen 16. Other type sources of fluid may
be used instead of a syringe, such as a collapsible reservoir or a
mechanical pump.
[0094] An irrigation lumen 20 may be provided to deliver irrigation
fluid to the body cavity. One end of irrigation lumen 20 extends
through a port at the distal end 10 of catheter A. The other end is
connected to a source of irrigation fluid (not shown).
[0095] The distal end 10 of catheter A and balloon 14 are both made
entirely of soft, compliant material, for example, silicone, so as
not to injure any body tissue.
[0096] Balloon 14 surrounds the distal end 10 of catheter A and
preferably has a toroidal shape when fully inflated. Supply lumen
16 is connected to balloon 14 through a fluid inlet 24 proximate
the distal end 10 of the catheter to permit the inflation fluid to
be introduced into balloon 14 to inflate the balloon and to be
removed from the balloon to deflate the balloon.
[0097] The apparatus of the present invention, generally designated
C, is connected between the source of pressurized inflation fluid,
in this case syringe 18, and the other end 24 of the supply lumen.
The pressure of the fluid within balloon 14 is limited to a
predetermined pressure level by apparatus C, such that the balloon
cannot apply a pressure beyond a predetermined level on the
surrounding tissue which will injure the patient. As the balloon is
inflated by the inflation fluid, apparatus C avoids over inflation
of the balloon by preventing additional fluid from being provided
to the balloon when the fluid pressure of the balloon reaches a
preset level.
[0098] In the preferred embodiments of the present invention which
use the pressure monitoring approach, apparatus C is connected to
balloon 14 by a second, return lumen 26 through a fluid return port
28 in the balloon such that apparatus C can monitor the pressure in
the balloon. As best seen in FIG. 2, which is a cross-section of
catheter A, supply lumen 16 and return lumen 26 extend between
apparatus C and the balloon, separately, in side-by-side relation,
preferably within the outside profile of the catheter.
[0099] In some of the preferred embodiments of the invention, the
pressure in the return line is used to deflect a flexible element
which functions as a valve. The flexible element forces a seal
which closes to block the balloon inflation line when the pressure
in return lumen 26, and thus in balloon 14, exceeds a
pre-determined level. The valve may be sealed by means of a
membrane, a diaphragm, a balloon, or any flexible element that
deforms with sufficient force when pressurized to apply sealing
force to the valve.
[0100] The flexible element can act with an over-center spring
member that is displaced when a predetermined force is applied to
it. The pressure responsive spring member allows the valve to
remain open until it is forced closed under sufficient balloon
pressure. The spring member may take the form of a disc, a dome, a
leaf spring, or any spring configuration that can be significantly
displaced when a predetermined force is applied.
[0101] The spring member may be configured to return to its rest
position once the applied force drops below the threshold level. Or
it may take the form of a bi-stable member that requires manual
resetting. This configuration allows the valve to stay fully open
regardless of fill pressure or fill flow rate, and causes it to
close rapidly when the balloon reaches the desired pressure,
regardless of fill pressure or flow rate. An alternate flow path
may be supplied with a one-way check valve to allow fluid to be
removed from the system to deflate the retention balloon when
necessary.
[0102] FIG. 3 is a cross-sectional view of a configuration of a
first version of a first preferred embodiment of the present
invention. The apparatus takes the form of a body 30 which includes
a base 32 and a pressure cap 34. Body 30 is connected to both
supply lumen 16 and return lumen 26 of a balloon catheter.
[0103] Base 32 includes a first passage 40 which includes sections
40a and 40b. Passage 40 extends the entire length of body 30,
between a fluid inlet port 42, which is designed to accept a
connector associated with the source of pressurized fluid, and a
fluid outlet port 44, which is connected to end 24 of supply lumen
16. It provides a fluid connection between the source of
pressurized inflation fluid and fluid inlet 22 of the balloon. A
valve (not shown in this figure) is pressed into the socket which
forms inlet port 42 to allow coupling of the body to a fluid supply
device such as syringe 18.
[0104] Pressure cap 34 has a second chamber 46 which includes
sections 46a and 46b. Passage section 46a is connected to a return
port 48 which in turn is connected to return lumen 26, and hence to
balloon 14 through fluid return port 28. Thus, the fluid pressure
in passage 46 is essentially the same as the pressure in the
balloon. The flexible valve element is situated under chamber
section 46b, as explained below. A plug 36 is used to seal an
opening in pressure cap 34 at the end of section 46a which is
required to withdraw a mold core.
[0105] In this preferred embodiment, the flexible element takes the
form of a flexible valve membrane 50 which is glued to the top
surface of base 32 such that when pressure cap 30 is fitted over
base 32, membrane 50 is situated under section 46b. Within base 32
are spaced, parallel channels 52 and 54 extending from passage
sections 40a and 40b, respectively. Channels 52 and 54 terminate at
spaced locations under membrane 50. Accordingly, a fluid connection
between passage section 40a and passage section 40b through channel
52, under membrane 50, and through channel 54, is formed.
[0106] In normal filling, fluid flows into passage section 40a from
the pressurized fluid source through the inserted valve (not shown
in this figure) in inlet port 42. The pressure forces a fill check
valve hall 56 within passage section 40a against the port between
passage sections 40a and 40b, closing that port. That forces fluid
to flow up through channel 52, under membrane 50 over and back down
channel 54 to the passage section 40b. The fluid then flows out
port 44 and through supply lumen 16 to the catheter balloon.
[0107] Return pressure comes back from the balloon to apparatus C
through return lumen 26. The return lumen connects into return port
48 of the body such that chamber 46a receives the pressure from
balloon 14. The pressure builds in the chamber section 46b until
the critical level for an indicator pop dome 58 situated on the top
surface of the pressure cap is reached. At that point, dome 58
expands outward, indicating that the appropriate pressure has been
reached.
[0108] Situated within chamber section 46b is a domed-shaped
pressure-responsive valve member 60. Member 60 is located over
membrane 50 and divides chamber section 46b into two portions 62
and 64. Portion 62 of passage section 46b is connected to the
return lumen through chamber section 46a and port 48.
[0109] As inflation of the retention balloon continues, the
pressure in portion 62 of chamber section 46b increases until the
pressure-responsive valve member 60 collapses, pressing membrane 50
down against the top surface of base 32, at a point between the
ends of channels 52 and 54 to close the fluid connection between
channels 52 and 54, stopping fluid flow the balloon. To allow
member 60 to collapse, the air under member 60 must be allowed to
escape. This is done through a pressure relief channel 66 which
vents portion 64 of chamber section 46b to the environment.
[0110] To empty the balloon, fluid is drawn from inlet port 42. The
reduction in pressure draws the fill check valve ball 56 away from
the port between passage sections 40a and 40b, allowing fluid to
flow out directly from passage section 40b to passage section 40a
around ball 56. This is also creates suction which will collapse
the membrane against the top surface of base 32.
[0111] The pressure-responsive member 60 can be made as or joined
with a bi-stable structure, such as snap dome or any of the other
embodiments described herein. Preferably, the pressure-responsive
member is constructed to enable a definitive snap shut off of flow,
making the difference between open and closed states of the valve
more distinct and consistent as the flow path will be either
totally open or totally closed when the target pressure is reached,
regardless of how quickly the balloon is filled. It is also
possible to fabricate such a bi-stable member to make a sound
indicating to the user that the valve is closed.
[0112] Member 60 may act in concert with a separate spring element
68, as shown in FIG. 4. FIG. 4 is a cross-sectional view of a
second version of the first preferred embodiment of the present
invention. This version is the similar to the first version shown
in FIG. 3 with the addition of dome-shaped spring element 68
situated under member 60. Element 68 may have several openings
therein, as shown. Element 68 urges member 60 towards the position
shown in the drawing, remote from membrane 50.
[0113] To aid in positive closure of the connection between
channels 52 and 54 as member 60 is moved by excess pressure in
portion 62 of chamber section 46b to a position against membrane
50, a protrusion 70 may be provided on member 68. Protrusion 70
concentrates the force of member 60 on the membrane 50 at the point
of the fluid connection between channels 52 and 54. This
force-concentrating function could be performed by a separate
component, an element integral with member 60, or a protrusion
integral to the spring element, as shown.
[0114] High pressure fill is shut off through the mechanical
advantage of the large pressure-responsive valve member 60
countering the small open area under membrane 50. The pressure of a
syringe fill can reach 1000 mmHg so if the desired shutoff pressure
is 35 mmHg, a ratio of 29 or more is required. If the channels 52
and 54 are 2 mm in diameter, for example, the open area under the
membrane can be limited to about 18 square mm. This means that the
area of the pressure-responsive member should be about 522 square
mm or a diameter of about 13 mm. Smaller ratios would he acceptable
as the snap shutoff would be a distinct enough change to indicate
that filling should stop. Larger ratios may be desirable if a snap
action spring element is employed, as additional force may be
needed to change the state of the spring element.
[0115] FIG. 5 illustrates a third version of the first preferred
embodiment of the present invention. This version of the apparatus
is similar to that of FIG. 3, with the following exceptions. Base
32 and pressure cap 34 each have a somewhat different shape. In
particular, cap 34 has a protruding top portion 59 enclosing a "V"
shaped pressure indicator 58. The member 60 and separate spring
element 68 are replaced by a bi-stable pressure-responsive valve
member 61 in the form of a snap dome with a truncated conical
shape. Further, in this version, a separate concentrating disc 72
is situated over membrane 50.
[0116] In a fourth version of the first preferred embodiment, shown
in FIGS. 6 and 7, to separate flow paths between fluid inlet port
42 and fluid outlet port 44 are created, one for inflation and a
second for deflation. Creating separate fluid flow paths eliminates
the necessity for having a discrete check valve, such as fill check
valve ball 56, with passage section 40b.
[0117] In this version, body 30 of the apparatus takes the form of
a hollow cylindrical member 30a which has a rigid top surface 80
upon which the flexible element, in the form of membrane 50, is
supported. Surface 80 has four openings or ports therein which are
situated over the ends of branches of the channels which connect
passage sections 40a and 40b, as explained below. In this version,
membrane 50 has an opening 82 therein.
[0118] A rigid or semi-rigid disc-like retainer 84 is situated over
membrane 50 to hold the membrane in place on surface 80. Retainer
84 may be fixed in place in any suitable manner, such as with
fasteners, a snap fit, or by bonding it to body 30a. The retainer
maintains sealing contact between membrane 50 and surface 80 of
body 30a. It includes features that define the areas within which
the membrane can flex and allow flow beneath it between desired
branches. In particular, retainer 84 has an oval-shaped opening 86
that permits the membrane to flex and allow flow beneath the
membrane between branches 52a and 54a and therefore from the inlet
42 to the outlet 44. Furthermore, retainer 84 has an oval shaped
relief 88 in its bottom surface that permits the membrane to also
flex and allow flow beneath the membrane between branches 54b and
52b and therefore from the outlet 44 to the inlet 42.
[0119] As is best seen from FIGS. 8a-8c, directional control of
flow between passage sections 40a and 40b may be achieved by
creating two separate flow paths. In order to do that, each of the
channels 52 and 54 is separated into two branches 52a, 52b, and
54a, 54b, respectively, as and 52a illustrated in FIG. 8a.
[0120] The flow paths under membrane 50, between branches 52a and
54a, and between branches 54a and 54b, are separated from one
another, either by retainer 84 or by selective bonding of the
membrane to the valve seat surface 80. Opening 82 in membrane 50 is
aligned with the end of branch 52b, as shown in FIG. 7. The area
above the membrane between branches 54b and 52b is enclosed by
relief 88, which prevents fluid that passes through opening 82 from
escaping this area.
[0121] As is best seen in FIG. 8b, during inflation, fluid can flow
from branch 52a to branch 54a, under the portion of membrane 50
aligned with opening $6 in retainer 84. Once the target fluid
pressure in the retention balloon is reached, that pressure is
present in portion 62 of passage section 46b (see FIG. 7), and
causes member 60 to move to its normal position remote from
membrane 50 shown in the drawing to a second position, against the
urging of spring 68. Movement of member 60 and spring element 68 to
that position causes protrusion 70 on spring 68 to move through
opening 86 in retainer 84, pressing the aligned portion of membrane
50 toward surface 80, and cutting off the flow from branch 52a to
branch 54a, in the same manner as in the aforementioned versions of
this preferred embodiment. Alternately the protrusion 70 may be
mounted to the top surface of the membrane, concentric with branch
52a.
[0122] Once the connection between branches 52a and 54a is
obstructed, fluid pressure is directed through branch 52b and
opening 82 in membrane 50. That pressurizes the surface of membrane
50 above branch 54b and bounded by relief 88, preventing fluid flow
into branch 54b. In this condition, fluid flow out of outlet port
44 is prevented.
[0123] When fluid is withdrawn from the balloon, as shown in FIG.
8c, the fluid flows into body 30a from outlet port 44, passes
through branch 54b, under membrane 50 into branch 52b, and out of
fluid inlet port 42. Under this condition, negative pressure in
branch 52a holds the membrane 50 against surface 80, and flow
through the body is conducted between branch 54b and branch 52b,
and ultimately to passage section 40a and inlet port 42. Under this
condition, opening 82 in membrane 50 causes pressure on either side
of the membrane to equalize. This prevents the membrane from
blocking flow between branches 54b and 52b.
[0124] A first version of a second preferred embodiment of the
present invention is illustrated in FIG. 9. In this version, the
body 30b of apparatus C has a fluid inlet port 42, a fluid outlet
port 44 connected to the fluid inlet of balloon 14 by supply lumen
16, a passage 40 extending from fluid supply port 42 to fluid
return port 44, a passage 46 and a return port 48 connecting
passage 46 to balloon 14 by return lumen 26, as in the first
preferred embodiment, but with a somewhat different layout.
[0125] However, in the second preferred embodiment, a pressure
relief valve 90 is located in passage section 46b to allow excess
fluid to escape from the balloon, but only during inflation of the
balloon. Fluid flow from the balloon, through return port 48 and
passage section 46a into passage section 46b is prevented b a pair
of valves 92 and 94. Valves 92 and 94 are mechanically connected to
work together by a connector 96 which extends through a channel 98
between passage 40 and passage 46.
[0126] The first valve 92 is situated in passage section 40a
between fluid input port 42 and passage section 40b which in turn
is connected to fluid outlet port 44. The second valve 94 is
situated in channel 98 between passage sections 46a and 46b, thus
between return port 48 (and thus the fluid outlet 28 of the
balloon) and pressure relief valve 90. Connector 96 causes first
valve 92 and second valve 94 to move together from a closed
position to an open position (shown in the drawing) in response to
the connector associated with the pressurized fluid source, shown
in this figure as the tip of syringe 18, being received in fluid
inlet port 42 of the body.
[0127] Connector 96 may take the form of mechanical means extending
between passage Section 40b and passage section 46b. A seal 100 is
provided for sealing channel 98 such that fluid cannot flow from
passage section 40b to passage section 46b.
[0128] Spring means 102 associated with valve 92 are provided for
urging valve 92 and valve 94 to move from the open position toward
the closed position.
[0129] In a second version of the second preferred embodiment, as
illustrated in FIG. 10, valve 94 is replaced by a "duckbill" valve
104 which is opened through lateral deformation of the valve.
Otherwise, the structure and operation of the apparatus is
essentially the same as in the first version of the second
preferred embodiment.
[0130] In a third preferred embodiment, the pressure relief valve
is eliminated and the valve in chamber section 40a is no longer
actuated to open in response to the insertion into fluid inlet port
42 of the connector associated with the pressurized fluid source.
However, there is still a spring-loaded valve 110, including a
spring 112, associated with fluid inlet port 42 to prevent fluid
horn escaping through that port when the connector is not
present.
[0131] In the first version of the third preferred embodiment,
illustrated in FIG. 11, the fluid flow preventing means includes a
normally open valve 114 situated in passage 40 between the fluid,
input port 42 and the fluid outlet port 44. A portion of the
external wall of the body 30c which defines chamber 46, has an
opening 116. Situated within opening 116 in the body wall is a
flexible means, such as a membrane or a diaphragm 118, which is
moveable between the position shown in the drawing, to an extended
position in the direction of the arrow. There is also an opening
120 in the wall which defines passage 40 and an opening 122 between
passage 40 and passage 46. Openings 120 and 122 are aligned with
each other and with opening 116. Flexible seals 124 and 126 are
provided to seal openings 120 and 122, respectively.
[0132] A connector 128 extends between flexible means 118 and valve
114 such that valve 114 moves with flexible means 118. In the
position shown in the drawing, valve 114 opens passage 40 and
allows fluid how between fluid inlet port 42 and fluid outlet port
44 to permit inflation of the balloon. However, when the pressure
in the balloon, and hence in chamber 46, exceeds a pre-determined
level, flexible means 118 will move to its extended position, in
the direction of the arrow. That will cause connector 128 to close
valve 114, preventing additional fluid from entering the balloon.
Connector 128 can move freely through openings 120 and 122 without
any fluid transfer through those openings due to seals 124 and
126.
[0133] In a second version of the third preferred embodiment,
illustrated in FIG. 12, normally open valve 114 is still present in
passage 40 and still permits inflation of the balloon until the
predetermined pressure level is reached. However, in this version,
valve 114 is mounted on a flexible seal 115, and opening 116 in the
external body wall and flexible means 118 are replaced by flexible
means 130, situated in chamber 46, which is moveable between its
normal open position and a second position, the latter position
being illustrated in the drawing. Means 130 in this version may
take the form of a diaphragm. Drawing needs fixing
[0134] Connecting means 128 connects flexible means 130 and valve
114 for closing valve 114 when flexible means 130 is moved from its
normally open position to the second position, shown in the
drawing, by the fluid pressure in chamber 46 exceeding the
predetermined level.
[0135] In a third version of the third preferred embodiment,
illustrated in FIG. 13, flexible means 130 takes the form of
bi-stable means, preferably a dome-shaped member 132. The
dome-shaped member 132 may be formed of rigid or semi-rigid
material. In this figure, valve 114 is shown in its normally open
position but is moved to a position dosing passage 40 in response
to the pressure in passage 46 exceeding the predetermined
level.
[0136] In a fourth version of the third preferred embodiment,
illustrated in FIG. 14, flexible means 130 takes the form of a
diaphragm 30 which is situated between the dome-shaped member 132
and chamber 46. In this figure, dome shaped member 132 is shown in
its flexed position, closing valve 114 such that no additional
fluid can he supplied to the balloon though passage 40.
[0137] In a fourth preferred embodiment of the present invention,
an inflatable return balloon, connected to retention balloon 14
through return lumen 26 and fluid return port 48, is situated
within passage 46 of body 30c of the apparatus. The return balloon
controls the fluid flow through passage 40. When the return balloon
is inflated by a pressure exceeding the pre-determined pressure
level in the retention balloon, it prevents further fluid from
flowing through passage 40 to balloon 14.
[0138] The first version of the fourth preferred embodiment,
illustrated in FIG. 15, is similar in structure to the versions of
the second preferred embodiment except that return balloon 140
replaces flexible means 118 of FIG. 11, diaphragm 130 of FIG. 112,
done-shaped member 132 of FIG. 13 or the dome-shaped/diaphragm
combination of FIG. 14, as the means for moving the valve within
passage 40.
[0139] As shown in FIG. 15, return balloon 140 is connected to
return port 48 and hence to balloon 14 through return lumen 26 and
balloon return port 28. The fluid flow preventing means includes
valve 114 situated in passage 40, between the fluid inlet port 42
and the fluid outlet port 44. Connector 128 extends between the
return balloon 140 in passage 46 and valve 114 such that the valve
is closed by the inflation of the return balloon 140, when the
fluid pressure in the fluid outlet 128 of the retention balloon
exceeds the given pressure level.
[0140] Preferably, return balloon 140 has a toroidal shape and
defines a central opening. Connector 128 extends though the central
opening in the return balloon.
[0141] A second version of the fourth preferred embodiment is
illustrated in FIG. 16, which is a cross-sectional view of a
different configuration apparatus body 30d and FIG. 17 which shows
the apparatus in perspective view. In this version, passage 40
takes the form of a flexible tube 142. The return balloon 140 in
passage 46 closes flexible tube 142 to cut off fluid flow to
retention balloon 14 when return balloon 140 is inflated by
pressurized fluid in the fluid outlet 28 of the retention balloon
exceeding the predetermined pressure level.
[0142] Preferably, flexible tube 142 has first and second
substantially parallel sections 142a and 142b. The parallel
sections 142a and 142b are connected by a "U" shaped section 144.
The return balloon 140, when inflated with fluid beyond the
predetermined pressure level, presses on parallel sections 142a,
142b of tube 140 to close the tube and prevent further fluid flow
to the retention balloon.
[0143] A pressure plate 146 may be interposed between the return
balloon 140 and flexible tube 142, adjacent parallel sections 142a
and 142b. A pressure indicator 148 associated with pressure plate
146 may be used as a visual indicator of the fluid pressure in the
retention balloon.
[0144] The fifth preferred embodiment of the present invention is
illustrated in FIGS. 18 and 19. In this embodiment, a valve 150 is
associated with fluid, inlet port 42. Valve 150 is normally in a
closed position. The valve is moveable to an open position when a
Luer-type connector 152 associated with a pressurized fluid source
is received in the fluid inlet port 42 of the body.
[0145] In the first version of the fifth preferred embodiment,
illustrated in FIG. 18, the over inflation preventing means
includes a port 154 in passage 46. A duckbill check valve 156 is
associated with port 154. A pivot arm 158 is actuated by the
Luer-type connector 152 associated with the pressurized fluid
source being received in the fluid inlet port 42 of the body to
open the duckbill check valve 156. Opening the duckbill check valve
156 allows excess fluid to escape passage 46 and hence prevent over
inflation of the retention balloon.
[0146] FIG. 19 illustrates a second vet of the fifth preferred
embodiment of the present invention. This version is similar to the
version illustrated in FIG. 18 except that an umbrella pressure
relief valve 160 is situated in passage 46 between the fluid outlet
of the retention balloon and duckbill check valve 156. The flexible
structure of umbrella valve 160 urges the umbrella valve toward the
closed position. However, when the pressure in the retention
balloon exceeds the predetermined pressure level, umbrella valve
160 will open allowing excess fluid to pass and be expelled during
inflation, when the Luer-type connector is received in fluid inlet
port 42, opening the duckbill valve 156.
[0147] In all of the above preferred embodiments, the connector
associated with the pressurized fluid source may take the form of a
portion of a syringe or a Luer-type connector. Further, means for
visually indicating when the pressure of the fluid in the retention
balloon exceeds the pre-determined pressure level may be employed.
For example, as seen in FIGS. 3, 4 and 5, the pressure indicating
means may take the form of a means associated with the wall of
passage 46 which is movable between a normal position and an
extended position. The pressure indicating means moves from its
normal position to its extended position in response to the fluid
pressure in the second passage exceeding the predetermined
level.
[0148] In the volume monitoring approach to the over inflation
problem, three different preferred embodiments are described, as
follows.
[0149] The sixth preferred embodiment of the present invention is
illustrated in FIGS. 20 through 25. FIGS. 20 and 21 show the
arrangement of the components of this embodiment, before and after
balloon inflation, respectively. A paddle wheel is used to monitor
the volume of fluid provided to and removed from retention balloon
14. Paddle wheel 170 is connected to a manually actuated syringe
18. Associated with paddle wheel 170 is a pressure accumulator 172.
The paddle wheel 172 rotation operates a valve 174 situated between
the paddle wheel and supply lumen 16. Valve 174 is closed to
prevent additional fluid from being provided to the retention
balloon when the volume of fluid in the balloon exceeds a
predetermined level.
[0150] All fluid flow into and out of the retention balloon is
forced to pass through paddle wheel 170. The paddle wheel 170 is
rotated by the fluid flow. If the fluid is incompressible, the
paddle wheel rotation 172 will accurately monitor the amount of
fluid passing, through the paddle wheel. When the desired amount of
fluid is in the retention balloon, the accumulated rotation of the
paddle wheel causes valve 174 to close, preventing additional fluid
from flowing into the retention balloon and hence over inflation of
the retention balloon.
[0151] FIG. 20 shows that as force is applied to the plunger of
syringe 18, fluid flows through the paddle wheel housing 180,
rotating the paddle wheel 170 therein, and through valve 174 which
is open, up the supply lumen 16 and into retention balloon 14. As
shown in FIG. 21, as additional force is applied to the plunger of
syringe 18, the paddle wheel continues to rotate until the
predetermined volume of fluid has been provided to the retention
balloon. At that point, the accumulated rotation of the paddle
wheel result in valve 174 being closed, preventing further fluid
from entering the retention balloon.
[0152] FIG. 22 is a perspective view showing the components of this
embodiment in greater detail. FIG. 23 is an exploded view of the
components. FIGS. 24 and 25 show in detail the mechanical
connection between the paddle wheel the valve.
[0153] The paddle wheel 170 is situated in a housing 180. Housing
180 has an inlet port 182 connected to receive fluid from the
syringe and an outlet port 184 connected to the retention balloon
through supply lumen 16 and valve 174. In this embodiment valve 174
takes the form of a sleeve valve. Valve 174 has a cylindrical
housing 183 and an internal valve body 185 which rotates within
housing 183.
[0154] A cam follower member 186 is fixed to the end of the
rotatable valve body 185 such that rotation of the cam follower
member causes the valve body to rotate within the valve housing.
The valve body 185 is hollow and has aligned fluid ports 188 on
either side, only one of which is visible in FIG. 23. When the
valve body is in the position shown in FIG. 23, the valve is closed
and no fluid can flow from the syringe to the retention balloon.
When the valve body is rotated by the cam follower member 90
degrees, ports 188 of valve body align with port 184 of valve
housing 183 and supply lumen 16 such that fluid can flow from the
syringe to the retention balloon.
[0155] Valve cam 190 is situated on the end of housing 180. It has
a cylindrical configuration with an open end which faces the paddle
wheel within housing 180. As seen in the cut-away portion of the
valve cam in FIG. 23, the interior surface of the side wall of
valve cam 190 has a circumferential channel 190 with an L-shaped
end, best seen in FIGS. 24 and 25.
[0156] Valve cam 190 is rotated by cam drive gears 192 between a
valve closed position shown in FIG. 24 and a valve open position
shown in FIG. 25. The valve cam is normally in the valve open
position as fluid is provided from the syringe to the retention
balloon and paddle wheel 170 is rotated. The diaphragm 194 of
accumulator 172 allows a limited volume of fluid to collect in the
accumulator. The fluid stored in the accumulator allows enough
fluid volume to be withdrawn to permit the paddle wheel to rotate
in a reversed direction sufficiently for the valve to reopen.
[0157] FIGS. 24 and 25 show the "L" shaped end of channel 196. When
valve cam 190 moves from the valve open position of FIG. 25 to the
valve closed position of FIG. 24, cam follower member 186 is
rotated one quarter turn in the counterclockwise direction. That
causes valve body 185 to rotate to close valve 174 and prevent
additional fluid from entering the balloon. When the plunger of the
syringe is withdrawn from the syringe body to deflate the retention
balloon, the vacuum caused by the withdrawal of the plunger causes
the paddle wheel 170 to rotate in the opposite direction, which in
turn causes the valve cam 190 to return to its valve open position.
That opens valve 174 and allows the fluid in the retention balloon
to flow back into the syringe.
[0158] A seventh preferred embodiment of the present invention is
illustrated in FIGS. 26, 27 and 28 which show the apparatus prior
to balloon inflation, after balloon inflation and during balloon
deflation, respectively. In this preferred embodiment, the fluid
system is closed, meaning that a fixed amount of fluid remains in
the system but is transferred between a collapsible reservoir and
the retention balloon.
[0159] As seen in these figures, this embodiment of the apparatus
includes a fluid reservoir 200 with a rigid bottom housing 201
having one section with a collapsible top 202. Applying pressure to
top 202 reduces the interior volume of the reservoir forcing fluid
from the housing into retention balloon 14 through supply lumen 16.
Situated within the other section of housing 201, between the
section with collapsible top 202 and the connection to the supply
lumen, is a set of three pressure indicators 206 which indicate
when the pressure in the retention balloon is low (L), medium (M)
or high (H). A Manually actuated valve 204 is located between
reservoir 200 and the supply lumen.
[0160] FIG. 26 shows the apparatus prior to inflation. In that
state, collapsible top 202 has a done-like configuration.
[0161] The balloon is inflated by applying pressure to the flexible
top 202 of reservoir 200 such that fluid is force out of reservoir
200 and into the retention balloon through pressure indicator 206,
open valve 204 and lumen 16. As seen in FIG. 27, when pressure is
applied to top 202, it collapses into the housing to force the
fluid into the retention balloon. When the pressure indicator 206
indicates that the pressure in the balloon has reached the desired
level, because a sufficient volume of fluid has been provided to
fully inflate the balloon, the operator closes valve 204.
[0162] As seen in FIG. 28, during deflation, valve 204 is opened by
the operator and the force applied to the top 202 of the reservoir
is released such that top 202 can return to its normal dome-like
shape. That causes fluid from the balloon to leave the balloon and
flow back into the reservoir, deflating the balloon.
[0163] An eighth preferred embodiment of the present invention is
illustrated in FIGS. 29 and 30. This embodiment also has a closed
volume system with a fixed amount of fluid and utilizes a variable
volume reservoir to provide fluid to and remove fluid from the
retention balloon. In this embodiment, the variable volume
reservoir takes the form of a syringe 18 with an associated
bellows-like portion 210. A manually actuated valve 212 is situated
between syringe 18 and supply lumen 16.
[0164] FIG. 29 shows the apparatus prior to balloon inflation. In
this state, bellows-like portion 210 is in its most extended
position such that the capacity of the syringe is at its highest
level. During the inflation process, as illustrated in FIG. 30,
force is applied to bellows-like portion 210 such that it
collapses, reducing the internal volume of the reservoir and
causing, fluid to move from the syringe, through valve 212 and
lumen 16 to the balloon. When the balloon is fully inflated, valve
212 is closed by the operator such that the fluid is retained in
the balloon. During deflation, valve 212 is opened and the fluid
from the balloon flows back into the syringe, causing bellows-like
portion 210 to expand as the balloon deflates.
[0165] A pressure gauge, or other means of indicating the pressure
in the system, not shown, may be used to alert the user when the
balloon is inflated to a desired pressure and the valve should be
closed. The total volume available to fill the balloon is limited
thus preventing gross overfill.
[0166] It will now be appreciated that the present invention
relates to a catheter retention balloon fill line shut off
apparatus that utilizes the pressure in a fluid return connection
to the balloon, separate from the fluid supply connection to close
a valve associated with the fill line to stop the inflow of fluid.
The fill line shut off apparatus is connected to or incorporated in
the fill port of the catheter.
[0167] In one preferred embodiment, pressure in the return line
expands or inverts a flexible element displacing a valve and
stopping flow into the balloon. The flexible element may be a
membrane, diaphragm, balloon or tube. A snap action spring may be
used for closing the overfill preventer valve when the pressure in
the balloon reaches a predetermined valve and the pressure in the
return valve actuates the snap action spring.
[0168] The flexible member is secured to a base to create a path to
carry fluid from the supply side port to the outlet side of the
valve. A pressure-responsive deforming member presses on the
membrane to seal the fluid flow path. The deformable member has an
area significantly larger than the flow area under the membrane to
permit the lower pressure of the retention balloon to stop the
higher pressure flow.
[0169] Preferably, the pressure-responsive member may take the form
of a dome. The member deforms suddenly when a predetermined
pressure is reached. The deformable structure incorporates or is
made as a snap dome.
[0170] The apparatus body is formed of two molded structures that
do not have flow passing between them except through the catheter
balloon. An integrated indicator that signals prior to or
simultaneous with the valve closing off may be provided. The
indicator is capable of expanding to indicate the pressure in the
return line.
[0171] A check valve controls a secondary flow path for removing
fluid from the balloon. The check valve element is a ball, flap,
duck bill, or umbrella valve. In another embodiment, the check
valve element consists of two or more additional ports in
conjunction with the flexible membrane.
[0172] The deformable structures are molded silicone rubber,
polyurethane or other thermoplastic elastomer.
[0173] In another preferred embodiment, a pressure relief valve
drains inside or outside of the catheter. The pressure relief valve
may be located inside or outside of the patient when the distal end
of the catheter is retained within the patient's rectum. The fluid
is only accessible to the pressure relief valve during inflation,
when the connector associated with the pressurized fluid source is
connected to the catheter.
[0174] In another embodiment, a Luer or other connector actuated
double valve is utilized to regulate fluid access to the relief
valve. The double valve includes a first valve with a valve System.
The valve stern extends into a chamber to open a second valve. The
second valve is a duckbill valve. The valve stem distorts the
duckbill valve to open it. The second valve includes a valve cap
and valve seat. The valve cap is held against the valve seat unless
the second valve is actuated. The first and second valves are
integrated into a single part.
[0175] In another embodiment, the overfill protector includes two
chambers, a fill chamber and a return chamber. A compliant sealing
element is mounted on said valve stem. The compliant sealing
element seals a stem opening between the two chambers when the
valves are actuated.
[0176] In another embodiment, a membrane is associated with the
valve stem. The return line fluid pressure expands or inverts the
membrane so as to pull the valve stem and close the fill line valve
stopping fluid flow into the balloon. A flexible membrane seal is
between the fill line and return line. The valve stem extends
outside the opposite side of the fill chamber with a flexible
membrane seal so as to balance the fill chamber pressure of the
valve stem. The seal between the fill line and the return line is a
sliding seal between the housing and valve stem.
[0177] In another embodiment, the balloon is inflated by the return
line causing a valve stem to close a valve on the fill line. The
balloon is annular or nearly annular and the valve stem passes
through the opening in the balloon.
[0178] In another embodiment, flexible tubing capable of being
crimped is part of the fill line. A return balloon inflated by the
return hue crimps the tubing stopping fluid flow into the retention
balloon. A stiff element may be situated between the crimpable
tubing and the return balloon. The stiff element concentrates the
force from the return balloon on the tubing. The stiff element may
also act as a pressure indicator.
[0179] While only a limited number of preferred embodiments of the
present invention have been disclosed for purposes of illustration,
it is obvious that many modifications and variations could he made
thereto. It is intended to cover all of those modifications and
variations which fall within the scope of the present invention, as
defined by the following claims.
* * * * *